the process by which cells obtain energy from glucose. During respiration, cells break down simple food molecules such as sugar and release the energy they contain.
two types of respiration
1. breathing-moving air in and out of lungs
2. cellular respiration
Two Stages of Respiration
1.first stage: takes place in the cytoplasm. There, molecules of glucose are broken down into smaller molecules. No Oxygen involved. small energy released
2. Second stage: in mitochondria. small molecules broken down into even smaller molecules. oxygen required and release a lot of energy.
powerhouses of the cell, where second stage of respiration takes place.
products of respiration
carbon dioxide and water. these diffuse out of cell during exhalation or breathing out.
raw materials of respiration
oxygen and sugar.
comparing photosynthesis and respiration
photosynthesis is opposite of respiration. During photosynthesis, carbon dioxide and water are used to produce sugars and oxygen. In respiration, the sugar glucose and oxygen are used to produce carbon dioxide and water. together these two processes form a cycle that keeps levels of oxygen and carbon dioxide fairly constant atmosphere.
an energy releasing process that does not require oxygen. Fermentation provides energy for cells without using oxygen. Amount of energy released by each sugar molecule is much lower than amount released during respiration.
when yeast or some other single celled organisms break down sugars. alcohol is one of the products. important to bakers and brewers. carbon dioxide produces air bubbles that cause bread to rise and cause bubbles in beer.
lactic acid fermentation
takes place in your body. occurs when cells lack oxygen. the fermentation supplies your cells with energy. product is lactic acid, the painful sensation in muscle.
6CO2 + 6 H2O -> C6H12O6 + 6O2
C6H12O6 + 6O2 -> 6 CO2 + 6 H2O